At the United States Department of Energy's Hanford Site in Eastern Washington State, radioactive material is stored in hundreds of underground storage tanks. Since 2001 Sluicer Tank Cannons developed and manufactured by AGI Engineering, have been used to break up and retrieve the material located in these tanks.
The Sluicer technology used at Hanford represents continued development from previous Sluicing systems AGI developed to clean crude oil and chemical tanks. These systems utilize a fluid jet from a nozzle to impact, break up, and liquefy in-tank material so it can be pumped out of the tank.
Building on this technology, AGI developed and manufactured the first Extended Reach Sluicer System (ERSS) in the summer of 2010. This new system placed the Sluicer nozzle on an arm capable of extending up to 30 feet or more, positioning the nozzle closer to the material in the tank in order to provide increased cleaning efficiency. Subsequent upgrades included the addition of high pressure, low flow nozzles to improve cleaning efficiency.
As with earlier generations of Sluicers the Extended Reach Sluicer System made extensive use of polymers and elastomers on the in-tank portion of the system. In order to survive the harsh radioactive and chemical environment specific polymers and elastomers (rubber and thermoplastic hoses and seals) were used to meet specific requirements.
Previously, polymers and elastomers have been used in three subsystems within the tank. First are the process hoses and seals that transmit water and recycled liquefier to the high and low pressure wash nozzles. Second are the hoses and seals within the hydraulic system that are used to operate the boom extension and retraction functions, as well as the nozzle elevation and transverse movement. The third set of polymer/elastomer components within the tank are the wear pads and rollers that control the movement of the telescopic boom tubes as well as the hoses within the unit.
However, polymer and elastomer components have a limited life on in-tank portions of the Sluicer equipment due to being subject to the radioactive environment, extreme chemical environments and wide temperature ranges. This technology can also be used to clean tanks filled with other combinations of chemical, radioactive, hazardous and/or other materials, however the limited life of the polymer and elastomer components restricts the use of these devices.
Thus, the need exists for solutions to the above problems with the prior art.